contador-lista-objetos-html

<template>
  <require from="./contador"></require>
  <require from="./precio"></require>
  <require from="converters/number-format"></require>
  <div>
    Total: <span>$ ${total | numberFormat:'0,0.00':'0'}</span>
  </div>
  <table class="table table-striped">
    <thead>
      <tr>
        <th>Producto</th>
        <th>Cantidad</th>
        <th>Precio</th>
        <th>Total</th>
      </tr>
    </thead>
    <tbody>
      <tr repeat.for="item of lista">
        <td>${item.Nombre}</td>
        <td>
          <contador objeto.bind="item"></contador>
        </td>
        <td>
          <precio objeto.bind="item"></precio>
        </td>
        <td class="TRight">
          $ ${(item.Precio ? item.Precio : 0) * item.Cantidad | numberFormat:'0,0.00':'0'}
        </td>
      </tr>
    </tbody>
  </table>
</template>

contador-lista-objetos.ts

import {bindable, computedFrom} from 'aurelia-framework';

export class ContadorListaObjetos {
  @bindable public lista = [];

  get total() {
    let totall = this.lista.reduce((prev, current, index, arr) => {
      let precioPrev = prev.Precio ? prev.Precio : 0;
      let precioCurrent = current.Precio ? current.Precio : 0;
      return precioPrev * prev.Cantidad + precioCurrent * current.Cantidad;
    });
    return totall;
  }
}